1. Field of the Invention
The present invention relates to a magnetic proportional current sensor including a magnetic core and a battery provided with the current sensor.
2. Description of the Related Art
In electric vehicles, a motor is driven using electricity stored in a secondary battery, and magnitude of motor driving current is detected by, for example, a current sensor. An example of the current sensor is a magnetic equilibrium current sensor (e.g., Japanese Unexamined Patent Application Publication No. 55-101057 and 2009-168644).
In the magnetic equilibrium current sensor, when measurement target current flows in a primary conductor, output voltage is generated in a magnetic detection element by primary magnetic field according to the measurement target current, a voltage signal output from the magnetic detection element is converted into current, and the current flows in a secondary conductor formed of a coil (negative feedback). The magnetic equilibrium current sensor is operated such that magnetic field (cancel magnetic field) generated by the current flowing in the secondary conductor and magnetic field generated by the measurement target current cancel each other out to be constantly 0. In this case, the current flowing in the secondary conductor is converted into voltage and is taken out as an output.
However, in the magnetic equilibrium current sensor, it is necessary that the voltage signal output from the magnetic detection element is converted into the current, the current is fed back to cancel magnetic field generated by the measurement target current, current (τ=L/R) of a coil as the secondary conductor is converted into voltage, and the voltage is taken out as an output. Accordingly, there is a problem that a response rate of current detection is lowered.